Thermoelectric ignition safety device



6, 1963 H. PUTZ ETAL 3,099,994

THERMOELECTRIC IGNITION SAFETY DEVICE Filed Feb. 10, 1961 2 Sheets-Sheetl Fig. 7

IN V EN TOR.

Aug. 6, 1963 H. PUTZ ETAL THERMOELECTRIC IGNITION SAFETY DEVICE 2Sheets-Sheet 2 Filed Feb. 10. 1961 24 Fig 7 27 j Fig.4

United States Patent 3,099,994 THERMOELECTRIC IGNlTlON SAFETY DEVICEHans Putz, Robert Lehnartz, and Ernst Feldman,

Remscheid, Germany, assignors to Job. Vaillant KG,

Remscheid, Germany Filed Feb. 10, 1961, Ser. No. 88,566 Claims priority,application Germany Feb. 11, 196i Claims. (Cl. 137-66) This inventionrelates to a thermoelectric ignition safety device, in particular forgas-water-heaters. As is wellknown, in a thermoelectric ignition safetydevice, the armature of a magnet thermoelec-trically energized by apilot burner is pressed on the magnet poles by means of a manuallyactuated member, and by the energized electromagnet a valve closure bodyis maintained in open position against the action of a valve spring. Itis well known to effect the pressing on of the magnet armature and theopening movement of the valve closure body by means of a lever as anintermediate member. With all prior art thermoelectric ignition safetydevices, the difficulty arises that the force exerted by the valvespring cannot be greater than the retaining power of thethermoelectrically energized magnet.

Therefore, if a thermoelectric ignition safety device is used, one hasto be satisfied with a relatively small closing force of the valvespring, which force often could not warrant for a safe sealing off.According to the inven tion this difiiculty is overcome in that makinguse of a lever as n intermediate memberknown per se11he supporting pointof the valve closure body lies on a shorter arm of the lever, and thepoint of engagement of the magnet armature lies on a longer arm thereof.

With such a structure, the force of the valve spring can be larger thanthe retaining power of the magnet by the ratio of the lever arms. Thelever can be both a one arm lever and a two arm lever or can be designedas an angle lever.

In :a particularly advantageous manner, such a thermoelectric ignitionsafety device can be combined with a manually operated valve system-wellknown per se which can be opened and closed at will and comprises a mainand an ignition gas valve, and which has two coaxial plate valves, oneof which is opened, by a pusher rod against the gas pressure and theother one of which is opened in the same direction by a driver after acertain stroke of said rod, in combination with contact piecenon-rotatably guided in the casing and axially movable by means of arotary control knob through a cam surface. In such a double valvestructure of successful construction a thermoelectric ignition safetydevice of the invention can be provided in such a manner that the driveris designed as a sleeve enclosing the pusher rod and directly abuttingthe contact piece, and that an additional push button is provided forthe actuation of the pusher rod, which axially penetrates the rotarycontrol knob and the contact piece and which at the same time engagesthe lever of the ignition safety device at the shorter lever armthereof, the lever of the ignition safety device being pivoted on thecasing and passing through the pusher sleeve through a diametral slotthereof. With such a structure, the upstream plate valve acting both asan ignition gas valve and as an ignition safety valve is opened bypushing down the push button, the magnet armature being pressed on atthe same time. The second downstream plate valve acting as main gasvalve is, however, opened through the contact piece and the pushersleeve by means of the rotary control knob. Thus two operating positionsare provided for the rotary control knob, namely Oil and On. Provisioncan be made without difiiculties that push button can be pushed downonly in the position Off [and is locked in the other position On. As theignition safety valve is retained in its open position by thethermoelectrically energized magnet, if the pilot flame burns, thedownstream main gas valve can be closed, with the pilot flame burning,by turning the rotary control knob into the position Off. Thus the pilotflame can be kept burning to prevent the apparatus from freezing up.

It is, however, not possible simply to extinguish the pilot flame byoperation of the rotary control knob and to close the ignition gasvalve.

It is well known, with thermoelectric ignition safety devices towithdraw the magnet armature from the magnet while the pilot flame isstill burning in order to close the ignition safety valve. This could berealized also in a device according to this invention. This has,however, the disadvantage that the apparatus can be, again, put intooperation at once. The magnet would then still retain the ignition gasvalve in its open position for a certain period without the pilot flameburning, which has been extinguished in the meantime. Thereby, theresulting danger is that unburned gas might escape.

In a further modification of the invention, the thermoelectric ignitionsafety device is constructed in such a manner that the ignition gasvalve is closed at the Off position of the rotary control knob, that,however, again putting the apparatus into operation is prevented untilthe armature of the thermoeleotrical-ly energized magnet has fallen off,i.e., until the thermocouple heated by the pilot flame has been cooleddown.

In order to achieve this, advantageously, provision is made in astructure of the type described hereinbefore, that the push buttonnon-rotatably guided in the rotary control knob comprises a locking boltguided non-rotatably but axially movable against the action of a springfixed to the casing, which bolt is coupled to the lever guiding thearmature, of the thermoelectric ignition safety device, and that uponrotation of the rotary control knob into its Ofi position an axiallyguided in non-rotatable manner pusher rod comes into engagement with aprojecting locking catch of the locking bol-t rotated with the rotarycontrol knob and thereby moves in axial direction relatively to thelever so that the valve returns into its closing position, while themagnet armature is still rerained. Thereby the blocking of the rotarycontrol knob effected by the locking bolt is automatically released notbefore then, when the lever guiding the magnet armature and the lockingbolt coupled thereto have returned to their initial positions after thearmature has been released.

An embodiment of the invention is shown in FIGS. 1-7 and is describedhereinbelow:

FIG. 1 is a sectional elevational view of a gas controller according tothe invention, and

FIG. 2 is a sectional plan View thereof.

FIGS. 3 and 4 show details of a blocking device.

FIGS. 5-7 are perspective views and show several operational positionsof the locking bolt and the parts cooperating therewith.

Within a gas controller casing 1, into which the gas enters in thedirection of the arrow, two coaxial valve seats 2 and 3 are provided.Valve seat 2 has a larger diameter than valve seat 3. An ignition gaspassage branches olf from an annular space 4 formed between the valveseats 2, 3. Behind the valve seat 3, as viewed in the direction of thegas flow, the main gas passage 6 is arranged leading to a burner (notshown).

A pot-shaped valve closure body 7 abuts the valve seat 2, which body isheld in closing direction both by the gas pressure and by a valve spring8 resting on the gas controller casing.

Another valve closure body 9 abutting the valve seat 3 is arrangedconcentrically to the valve closure body 7 and is pressed towards thevalve seat 3 by a valve spring 10 also in the direction of the gaspressure. The valve spring 10 is positioned within the pot-shaped valveclosure body 7 and rests thereon. A spacer rod 11' inserted into ablind-end bore 14 of the valve closure body 7 passes through the valveclosure body 7 in a seal 13 and extends into a control sleeve 12, whichis axially guided in a seal 12' in a partition wall 1' of the casing. Inthe interior of this sleeve 12 a pusher rod 11 is axially guidedcooperating with a spacer rod .11, and is sealed by means of a seal 11".

A rotary control knob '18 is turnably mounted on the gas controllercasing 1 by means of a cap nut 1. The rotary control knob has twodiametrically opposed cams 17 on the inner surface thereof whichcooperate with cam surface 17' of a contact piece 15 guidednon-rotatably in axial direction in the gas controller casing. If therotary control knob 18 is turned manually through about 90 from the Offposition shown to the On position, the contact piece 15 is shifted inaxial direction by the cams 17 running up the cam surfaces 17', wherebytwo compression springs 16 resting on the partition wall 1 are put understress. A blocking sleeve 19, shown separately in FIG. 3, is slippedover the control sleeve 12, which blocking sleeve extends into a centerhole of the contact piece 15 and abuts the partition wall 1". Theblocking sleeve 19 is milled out at the end extending towards thepartition wall 1', so that merely fork legs 19' are produced, whichbetween them take up flange projection 20 of the control sleeve. Theflange projections 20 abut within the recess of the front face of thecontact piece 15 so that, if the contact piece 15 is shifted,

th control sleeve 12 is shifted therewith, thereby, lifting the valveclosure body 9 from its seat, i.e. opening the main gas valve.

Ajpush-button 21 is mounted in the rotary control knob :18, which with ahollow shaft 21 projects from the rotary control knob and is guidednon-rotatably in the knob "18 by means of a fork-shaped extension 22,which is shown separately in FIG. 4. At the Off position shown of therotary control knob 18, the push-button 21 cannot by pushed down, as thefork-shaped extension 22 strikes against the front face of the blockingsleeve 19. The blockingsleeve 19 is, however, provided with suitablerecesses 19", extension 22 can enter into these recesses 19f, ifthe'r'otary control knob 18 is turned into an interrn ediate position,the Ignition position. Thus in this Ignition position the push buttoncan be pushed down. A flattened locking bolt 23 is arranged in the fork-'shaped extension 22 and is also guided non-rotatably in the rotarycontrol knob. The locking bolt 23 shown at an enlarged scale in FIGS. -7has a locking catch 24 at itsone end projecting the extension 22consisting of a blade produced by milling out 24'. The end of the pusherrod 11 extendingtowards the locking bolt 23 is provided with a blind-endbore 25 and with axial slot 26 corresponding to thethickness of thelocking catch 24. A threaded rod 27 is screwed into the locking bolt 23from the front face thereof, which rod extends into the slotted end ofthe pusher rod 11 provided with the blind-end bore 25. A lever 28 ispivotably connected to the threaded rod at pivot 28', which lever ismounted at 29 in the gas controller casing. The lever 28 passes throughthe 'control sleeve 12 through a slot 30 thereof and is lead out of thegas cont-roller casing 1 through a slot 31. The

lever 28 is pivotably connected at its projecting end with the pusherrod 32 of a magnet armature 33. The pusher "rod 32 is axially guided inthe casing 34 of a thermoelectric magnet.

Acompression spring 36 is housed in the shaft 21 of push button 21,which spring rests on locking bolt 23.

Additionally, a spring 37 is provided which, on the one hand rests onthe locking bolt 23 and on the other hand on the blocking sleeve 19fixed to the casing.

At the Off position of the rotary control knob 13 as shown in FIGS. 1and .2, the locking bolt 23 is in the position shown in FIG, 6. Asalready described hereinbefore, at this Ofl position the push button 21cannot be pushed down, since the fork-shaped extension .22 abuts theblocking sleeve 19.

If the rotary control knob 18 is turned into the position Ignition,where it is engaged by a catch device (not shown), the push button 21 isturned therewith so that the fork shaped extension 22 is positioned infront of the recess 19" of the blocking sleeve 19 and the locking bolt23 has the position shown in FIG. 5. In this position, the locking catch24 is transverse to the slot 26 of the pusher rod 11. As the lever 28cannot perform this rotation of the locking bolt 23, the threaded rod 27connected to the lever 28 in pivot point 28' is turned in its thread inlocking bolt 23. At this Ignition position the push button 21 can bepushed down. Thereby, the locking catch 24 shifts the pusher rod 11 andopens the ignition safety valve 7/ 2 against the action of valve spring8 by means of spacer rod 11', so that ignition gas can get through theignition gas passage 5 to the pilot burner. At the same time, when thepush button 21 is pushed down, the lever 28 is swung-out by means of thethreaded rod screwed into the locking bolt, so that the armature 33 ispressed on the poles of the thermoelectrically energizable magnet 35. Ifnow, with the push button 21 pushed down the pilot flame is ignited andin well-known manner the thermo-eurrent necessary to energize the magnet35 is produced by the heat of the pilot-flame, the armature 35 will beretained by the magnet 35, so that lever 28 cannot return into itsinitial position, when the push-button is released and returns under theinfluence of the spring 36. With the lever 28 held in the displacedposition, also the locking bolt 23 is retained by the threaded rod 27with the spring 37 put under stress, so that the pusher rod 11 remainsin its displaced position and the ignition safety valve 7/2 remainsopened.

It is essential that the forces of the valve spring 8 rthnough thepusher rod 11 and the locking bolt 23 as well as the forces of thespring 37 act in the point 28' on a shorter arm of the lever 28 than theretaining force exerted by the magnet 35 on the armature 33. Thereforethis retaining force can be smaller than the opposing spring forces 8and 37' by the ratio of the lever arm. Thus the lever 28 can be retainedby a relatively small 'magnetic force against the action of a relativelystrong ing bolt 23 and consequently opening ignition safety valve 7/ 2,the contact piece 15 and the pusher rod 12 abutting 'ereon is displacedaxially by means of the earns 17 and the cam surfaces '17 and thus themain gas valve 9/3 is opened. Now the gas is allowed to flow through thetwo open valves 7 /2 and 9/3 to the connecting socket 6. There a waterdeficiency safety valve 38 is provided in usual mmer, which is opened bya flow actuated member 40 through a pusher rod 39, if water flowstherethrough. Then the gas can be ignited in the burner (not shown) bythe burning pilot flame, whereby the apparatus comes into operation.

If for some reason the pilot flame is extinguished before the apparatusis put into operation, the armature of the magnet is released after acertain cooling down time, so that the lever 23 and the locking bolt 23return to their initial position under the influence of the spring 37.Thereby the ignition safety valve returns to its closed position underthe influence of the spring 8.

This device enables, however, also a closing of the ignition safetyvalve 7/ 2 with the pilot flame still burning, i.e. with retainedarmature 33 and still swung-out lever 28. If, namely, in this conditionthe rotary control knob 18 and thus also the locking bolt is returnedinto the Off position, the slot 26 of the pusher rod 11 can get intoengagement with the locking catch. Thereby the pusher rod 11 isdisplaced under the influence of the valve spring 8 and displaces thevalve closure body 7 returning into its closed position relatively tothe still retained lever 28 and the locking bolt 23, so that theposition shown in FIG. 7 is reached. By closing the ignition safetyvalve 7/2 the gas supply to the pilot burner through 5 is shut oil sothat the pilot burner is extinguished. During the cooling down timelasting several seconds, the rotary control knob cannot be turned intothe On position again, as otherwise unburnt gas could escape during thistime. This locking of the rotary control knob 18 is provided by theengagement of the locking catch 24 into the slot 26 of the pusher rod11, as shown in FIG. 7. If the armature 33 has been released by themagnet 35 after the cooling down of the thermocouple has taken place,the lever 28 and the locking bolt 23 can return into their initialpositions under the influence 0f the spring 37, so that the lockingcatch 24, as shown in FIG. 6, comes out of engagement and the locking ofthe rotary control knob 18 is released automatically.

Invention is claimed as follows:

1. In a gas valve including a body having a main gas supply connection,a pilot burner connection and a main burner connection, and including athermoelectric magnet means, the improvement comprising: a pilot valveincluding a first closure member in said body between the mainconnection and the pilot connection; first operating means operativelyconnected to the closure member and the electromagnet means to hold theclosure member open when the magnet means is energized and the pilotvalve is otherwise opened, said operating means including a manuallyoperable member to permit the pilot valve to be manually opened; a mainburner valve including a second closure member in said body between thepilot connection and the main burner connection; second operating meansoperatively connected to the second closure member and including amanually operable member to open the main valve and hold it open; andmeans interconnecting the firs-t and second operating means to preventthe main valve from being closed and thereafter reopened until aftersaid magnet means has been deenergized.

2. In a gas valve as set forth in claim 1, wherein said closure membersare coaxial with the second closure member being up stream, with respectto the flow of gas, of the first closure member, one of said actuatingmeans including a sleeve and the other of the actuating means includinga pusher rod positioned within the sleeve, said sleeve and rod beingaxially 'aligned with the closure members.

3. In a gas valve as set forth in claim 1, wherein the first operatingmeans includes a means to provide a mechanical advantage to the magnetmeans in holding the closure member of the pilot valve open.

4. A gas valve including: a hollow body having a gas inlet connection, afirst chamber communicating with the inlet connection and a secondchamber communicating with the first chamber, said body defining a firstvalve seat between the inlet connection and the first compartment and asecond valve seat between the first compartment and the secondcompartment, said two seats being coaxial, a pilot line connectioncommunicating with the first compartment, a main burner line connectioncommunicating with the second compartment; a first closure member seatedon the first seat; a second closure member seated on the second seat; asleeve journaled in the body coaxial with the seats with one end injuxtaposition to the seated side of the second closure member; pusherrod means journal-ed in the sleeve, extending through the second closuremember and in juxtaposition to a portion of the seated side [of firstclosure member; means resiliently urging said closure members againstsaid seats; a first operating means for the rod means to move the rodmeans axially to unseat the first closure member; a second operatingmeans for the sleeve to move the sleeve axially to unseat the secondclosure member; a lever pivotally connected to the body and to the rodmeans; electro magnet means connected to the lever to hold the rod meansin a position at which the first closure member is unseated when themagnet means is energized and the rod means is otherwise moved to saidposition; and means interconnecting the two operating means to preventthe sleeve from moving the second closure member to the unseatedposition, after both members have been unseated and the second closuremember reseated, until after said magnet means has been deenergized.

5. A gas valve as set forth in claim 4, wherein the second operatingmeans includes a rotary control knob having a cam moveable from an offposition toan on position to unseat the second closure member, anaxially moveable, non-rotatable cam follower operatively connected tothe cam and to the sleeve; said first operating means including a pushbutton extending through the control knob, and means operativelyconnecting the push button and the rod means to permit the push rod tobe moved by an inward push on the button only when the control knob isat an intermediate position between the on and o positions.

References Cited in the file of this patent UNITED STATES PATENTS2,313,890 Ray Mar. 16, 1943 2,395,470 Ewing Feb. 26, 1946 2,455,542Weber et al. Dec. 7, 1948 2,901,034 Puttfarcken ct al Aug. 25, 19592,917,062 Schuchardt Dec. 15, 1959

1. IN A GAS VALVE INCLUDING A BODY HAVING A MAIN GAS SUPPLY CONNECTION,A PILOT BURNER CONNECTION AND A MAIN BURNER CONNECTION, AND INCLUDING ATHERMOELECTRIC MAGNET MEANS, THE IMPROVEMENT COMPRISING: A PILOT VALVEINCLUDING A FIRST CLOSURE MEMBER IN SAID BODY BETWEEN THE MAINCONNECTION AND THE PILOT CONNECTION; FIRST OPERATING MEANS OPERATIVELYCONNECTED TO THE CLOSURE MEMBER AND THE ELECTROMAGNET MEANS TO HOLD THECLOSURE MEMBER OPEN WHEN THE MAGNET MEANS IS ENERGIZED AND THE PILOTVALVE IS OTHERWISE OPENED, SAID OPERATING MEANS INCLUDING A MANUALLYOPERABLE MEMBER TO PERMIT THE PILOT VALVE TO